Content Teasers for September 1999
Turning Theorems into Plays
After overhearing the gossip of the house staff, the young Thomasina Coverly
interrupts her algebra lesson on Fermat's Last Theorem to ask her tutor,
Septimus Hodge, the meaning of "carnal embrace." Septimus's
first explanation, "Throwing one's arms around a side of beef," proves
unacceptable as Thomasina points out that it was a certain Mrs. Chater
who was discovered in carnal embrace in the graden gazebo. "I don't
think you have been candid with me Septimus," Thomasina insists.
"A gazebo is not, after all, a meat larder." "Ah yes, I am ashamed,"
Septimus finally concedes. With blunt, almost medical precision,
he then provides his talented pupil with a terse description of intercourse,
explaining that carnal embrace is actually sexual congress between males
and females...
Septimus: ... for purposes of procreation and pleasure.
Fermat's last theorem, by contrast, asserts that when x, y, and z are whole
numbers each raised to the power of n, the sum of the first two can never
equal the third when n is greater than 2.
Thomasina: Eurghhh!
Septimus: Nevertheless, that is the theorem.
Cycloidal Areas without Calculus
For centuries mathematicians have been interested in curves that can be
constructed by simple mechanical instruments. Among these curves
are various cycloids used by Apollonius around 200 B.C. and by Ptolemy
around 200 A.D. to describe the apparent motions of planets. The
simplest cycloid is the curve traced out by a point on the circumference
of a circular disk that rolls without slipping along a horizontal line;
it forms a sequence of arches resting on the line.
WordWise: Arabic From A (Algebra) to Z (Zero)
Imagine that you were imprisoned on Alcatraz, and had just completed the
fourth year of a 25-year sentence for trying to divide by zero. The
cruel prison guards have tossed you in solitary confinement, and you've
been stripped of your calculator! Okay, how do you figure out the
number of days left in your sentence?
Chance Encounters: Probability: From Monte
Carlo to Geometry
The interplay between probability and other areas of mathematics often
occurs in unexpected places. Below you will see how probability can
be applied to problems in calculus, the estimation of e, and even
to geometrical proofs.
Kelvin's 100-year-old Bubble Conjecture Burst
The year 1994 brought striking news of the disproof of Lord Kelvin's 100-year-old
conjecture by Denis Weaire and Robert Phelan of Trinity College, Dublin.
To understand the problem, imagine an infinite soap bubble cluster filling
all of space. Suppose that each bubble encloses exactly one cubic
foot of air. What would be the most efficient shape for such a cluster,
minimizing the total area or surface energy of all the interfaces between
regions?
A Graduate School Primer
Who should go to graduate school? Where and why should they go?
What is graduate school? This note is a biased answer to some of
these questions. Keep in mind that the answers are provided by a
person who believes that education in general is a wonderful thing, has
no regrets about going to graduate school, and feels it led to an employment
position that almost ideally suits his ambitions and temperament.
This article addresses some of the preparations that should be taken by
students planning to go to graduate school, but provides only the basic
details. I do not pretend that it is a substitute for personal advice,
which I strongly suggest you obtain before making such an important decision.
A Half-Dozen Mathematical Activities to Try with Friends
For the past several years I have run, at St. Mary's College of Maryland,
a mathematics club with a unique flair. Although it has a social
aspect, that is not its primary aim, nor is it focused on preparation for
mathematics competitions. Rather, it attempts, through hands-on projects
and discussions, to illustrate a sense of fascination and delight with
mathematics, to foster a sense of curiosity, and to make sophisticated
mathematics accessible, intriguing and fun. Students who participate
range from freshmen to seniors, math majors to English majors. Even
faculty members have enjoyed participating!
Problem Section:
S-31.
Proposed by Suat Nomli, Student, Bilkent University, Turkey. Construct
an equiangular hexagon whose sides are 1, 2, 3, 4, 5, and 6.
S-32.
Proposed by William Bechem, Eastern Middle School and R.A. Rosenbaum, Wesleyan
University. Prove that the incenter of a triangle lies on its Euler
line (the line through the circumcenter and the centroid), if and only
if the triangle is isosceles.
S-33.
Proposed by Mircea Ghita, Stuyvesant High School. Solve for real
x:
(4^x)(9^{1/x})
+ (4^{1/x})(9^x)=72.
S-34.
Proposed by E. M. Kaye, Vancouver, BC. Can the sum of the squares
of 61 consecutive integers ever be a perfect square?
The Final Exam: Math Horizons t-shirt Contest
(To read the winning entry to April's Final Exam, click here.)
We all agree that math is beautiful. If you wander around
a math department you will undoubtedly see a professor or student who thinks
math is so beautiful that she is wearing some on her t-shirt. Over
the years we've seen lots of math t-shirts: some were clever, others
profound, some beautiful, most were just silly. Visual jokes are
popular, and we've all seen many Penrose and Escher graphics and Sidney
Harris cartoons. The American Statistical Association sells a shirt
bearing the phrase "I am statistically significant." top ten lists
are a perennial fashion statement among the numerical cognoscenti:
Top Ten Proof Techniques -- 1. Intimidation 2. Gesticulation
3. Circular Reasoning (See #3.) 4. Denial ...; Top Ten
Mathematical Pick-up lines -- 1. Voulez-vous Cauchy avec moi ce soir?
2. Hey baby, what's your sine? 3. Your LaPlace or mine?
4. Have we met? You Riemann me of someone. Our all-time
favorite may just be the emphatic CARPE THEOREM.
By now you've guessed it: the contest is to design an official
Math Horizons t-shirt. The winning design will embody the wit, wonder,
and playfulness that the magazine strives for in its articles. We
will also award prizes for best departmental t-shirt, best pun, and best
graphic. Send your design ideas to skennedy@carleton.edu,
or, if you want to try to influence the judges by sending us an actual
t-shirt (XXL) mail to Steve Kennedy, Math Department, Carleton College,
Northfield, MN 55057. The creators of winning designs will receive,
duh, a Math Horizons t-shirt and, of course, the usual everlasting fame
and glory. Deadlines for entries is November 1, 1999.